May I assume you're talking about a Pressure & Temperature relief valve on a hot water tank?
I'd say they shouldn't be related.
Did you happen to raise your temperature setting?
You say "had dripped". So it's not dripping any more?
I would keep an eye on it. Of course you know it could be from high pressure or high temperature.
If you have an expansion tank, that would be one of the first places to check.
Ideally having a temperature gauge and a pressure gauge would be nice in order to see if you ever get close to the limits.
I could go on but it may not be necessary at this point.
Yes your assumption is correct. No continuous drip. It seemed to release water then stop. It did not release more water when my kid showered shortly after the original release.
We did not make any adjustments to the water heater temperature. We did need to swap out the existing dishwasher water supply line (originally copper now braided) Could this have caused pressure issues?
Do you have an expansion tank(bladder tank)? Typically only required if you have something on you cold water service that would prevent the water from expanding when heated and which would quickly raise the pressure in the absence of a properly functioning expansion tank.
The P&T valve on the water heater are typically set to release water at 150 psi or a temperature at 210 degrees. If you don't have some type of thermostatically controlled mixing valve for your water coming out of your heater, I think you would of got an indication that the water temp was extremely high at some point.
Not sure if a slight water hammer(momentary spike in pressure somewhere in the system due to sudden stopping of flow) could cause it.
We don't have an expansion tank or an in line pressure reducing value. We do have occasional water pressure drops that end with a surge back up to pressure. I'm not sure if this is the same as the water hammer.
Since the hot water heater is 22 years old I'll start doing the research for it's replacement and keep an eye on it while I run the dishwasher again to see if it will duplicate the issue.